The instant invention relates to the field of dentistry and more particularly to a periodontal probe which is operable by a dentist for measuring the depths of the periodontal pockets in the gingival tissue in the mouth of a patient in order to monitor the progression of periodontal disease in the patient.
In recent years, periodontal disease has been recognized as one of the most widespread and serious dental afflictions encountered by dental patients. In this regard, it is well known in the dental field that periodontal disease is a progressive, plaque-induced affliction which can cause serious tissue inflammation, and therefore bone loss in the areas surrounding the teeth of patients. Further, it is generally known that in order to effectively treat periodontal disease, it is necessary to monitor the progression of the disease in the mouths of patients by monitoring gum recession, tissue condition and bone loss. Generally, this has been done by periodically visually examining the mouths of patients and by measuring the depths of any periodontal pockets in the gingival tissue surrounding the teeth therein. Originally, pocket depths were measured utilizing metal probes having calibration markings thereon. However, probes of this type were generally found to be awkward to use and manipulate in the mouths of patients, and they were often found to require time consuming measurement procedures which often produced results of questionable accuracy. More recently, however, more sophisticated electronic measuring probes having retractable tip portions have been developed which have been found to be capable of producing more accurate measurements of the depths of periodontal pockets in the mouths of patients. Devices of this type have generally been operable for generating electronic signals which are representative of periodontal pocket depths and for supplying these signals to various remote electronic recording and/or readout apparatus. Periodontal probes of this general type which represent the closest prior art to the subject invention of which the applicants are aware are disclosed in the U.S. patents to MOUSSEAU, U.S. Pat. No. 3,916,529; GRENFELL et al, U.S. Pat. No. 3,943,914; SUMPTION et al, U.S. Pat. No. 3,979,835; STARK et al, U.S. Pat. No. 4,164,214; ACKERMAN et al, U.S. Pat. No. 4,665,621; SIMON et al, U.S. Pat. No. 4,677,756; PIPPIN et al, U.S. Pat. No. 4,708,647; the Japanese Pat. application disclosure No. 59-40102 (1984) and the pending U.S. Pat. application to ACKERMAN et al, No. 07/024,991. However, these references fail to disclose or suggest a periodontal probe having many of the unique structural features and advantages of the periodontal probe of the subject invention, and hence they are believed to be of only general interest with respect thereto as will hereinafter be made apparent.
The periodontal probe of the instant invention comprises sequentially disposed, connected sensor, shaft and tip portions, and an elongated flexible fiber element which extends longitudinally through the tip portion and at least a portion of the shaft portion. The fiber element is assembled with the tip portion and the shaft portion so that the distal end of the fiber element normally projects beyond the free terminal end of the tip portion, and the fiber element is supported in the tip portion and the shaft portion so that it is longitudinally slidable therein along a predetermined path of movement. The sensor portion is adapted so that it communicates with the proximal end of the fiber element for sensing relative longitudinal movement between the fiber element and the tip portion. The shaft portion and the tip portion have a combined length of at least 41/2 inches (preferably approximately 6 inches), and the shaft portion is detachable from the sensor portion to permit replacement of the shaft portion, the tip portion and the fiber element. The sensor portion preferably includes an elongated sensor shaft having an aperture in the terminal end thereof, and the shaft portion preferably includes a tubular sleeve which is detachably received on the sensor shaft so that the proximal end of the flexible fiber element extends through the aperture in the sensor shaft and communicates with the sensor portion in the interior of the sensor shaft. The sensor portion preferably further comprises an elongated compressible coil spring in the sensor shaft having a substantially constant compressive force, an optical encoder strip holder in the interior of the coil spring, the encoder strip holder having an encoder strip on one end thereof, and an optical encoder element which is responsive to longitudinal movement of the encoder strip for generating electrical signals which cumulatively correspond to the longitudinal position of the encoder strip relative to the sensor element. The sensor portion is preferably further adapted so that longitudinal movement of the fiber element in the tip portion in a direction toward the sensor portion causes the coil spring in the sensor shaft to be correspondingly compressed while simultaneously causing the encoder strip to be longitudinally repositioned relative to the encoder element. The periodontal probe is preferably constructed so that the shaft portion is rotatable relative to the sensor portion to enable free manipulation of the shaft portion and the tip portion during use of the probe, and the tubular sleeve is preferably detachably snap-received on the sensor shaft. The tip portion is preferably formed in a substantially S-shaped configuration, including oppositely curved inner and outer portions having radii of curvature of between 0.25 inches and 0.75 inches. The fiber element preferably has a length of at least approximately 2 inches, and it is preferably made from a low hydroscopic nylon fiber Further, the fiber element preferably includes a terminal end portion having a series of annular bands thereon of different colors, and the end of the terminal end portion is rounded for ease of entry into the sulcus. The fiber element and the tip portion are preferably adapted so that the terminal end portion of the fiber element normally projects beyond the free terminal end of the tip portion, but so that the terminal end portion retracts into the tip portion as the fiber element is longitudinally advanced in a direction toward the sensor portion. In this regard, since the terminal end portion of the fiber element normally projects beyond the free terminal end of the tip portion, the terminal end portion is not prone to developing a curved or bent "set" which could adversely affect the operation of the probe.
It has been found that the periodontal probe of the instant invention can be effectively and easily utilized for measuring the depths of periodontal pockets in the mouth of a patient in order to monitor the progression of periodontal disease in the patient. In this regard, because the tip portion, the shaft portion and the fiber element are detachable from the sensor portion, they are readily adapted for sanitary disposable constructions; and because the tip portion and the shaft portion preferably have a combined length of at least approximately 41/2 inches, they are normally the only portions of the probe which come in contact with the mouth of a patient or the hands of a dentist during a periodontal examination. Accordingly, the risk of transmitting contagious diseases during a periodontal examination is substantially reduced with the periodontal probe of the instant invention. Further, because the shaft portion is rotatable relative to the sensor portion, the shaft portion, the tip portion and the fiber element can normally be freely and effectively manipulated in the mouth of a patient during the course of an examination. The optical encoder provides an effective and reliable means for measuring longitudinal movement of the fiber element, and the compressible coil spring is configured to provide nearly the same resisting force at both extremes of the fiber's travel, resulting in a substantially repeatable correlation between fiber position and resisting force applied to the fiber. Therefore, repeatable measurements are possible as the fiber element is used to probe the depths of periodontal pockets in the mouth of a patient. Further, because the fiber element is preferably made of a low hydroscopic nylon fiber and because it has a length of at least approximately 2 inches, it is generally not possible for saliva to migrate along the length of the fiber element via capillary action to a point where it can contaminate or otherwise adversely affect the sensor portion. Still further, because the tip portion has a series of annular bands thereon of different colors, it is normally possible for an operator of the probe to visually determine the extent by which the fiber element has been inserted into a periodontal pocket during a periodontal examination.
Accordingly, it is a primary object of the instant invention to provide a periodontal probe having a tip portion, a shaft portion and a fiber element which are disposable and readily detachable from a sensor portion of the probe.
Another object of the instant invention is to provide a periodontal probe comprising sequentially disposed, connected sensor, shaft and tip portions and an elongated flexible fiber element in the tip and shaft portions, wherein the shaft portion is rotatable relative to the sensor portion to permit free manipulation of the tip portion during a periodontal examination.
Another object of the instant invention is to provide a periodontal probe comprising sequentially disposed, connected sensor, shaft and tip portions and a fiber element in the tip and shaft portions, wherein the tip portion is formed in an S-shaped configuration to enable the fiber element to slide freely therein.
An even further object of the instant invention is to provide a periodontal probe comprising sequentially disposed, connected sensor, shaft and tip portions and a fiber element in the tip and shaft portions, wherein the fiber element is retractable into the tip portion and wherein the fiber element has a series of different colored annular bands on the terminal end portion thereof to provide a visual indication of the position of the fiber element relative to the gingival margin during a periodontal examination.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.